Many languages, such as English, utilize phonographic characters that consist of phonemes (i.e., speech sounds). As such, people may learn to read these languages by first learning different phonemes and thereafter “sounding out” words of which they are unfamiliar. Other languages, meanwhile, utilize logographic characters (e.g., Kanji characters) that consist of visual symbols representing words rather than phonemes or sounds. As such, learning logographic characters within these languages requires memorization rather than simply sounding out the characters. Because of this, if a person does not recognize a logographic character, no practical way exists for the user to sound out or otherwise determine the pronunciation of the character without some external reference source, such as a dictionary. Some languages, such as Japanese, utilize a combination of phonographic characters and logographic characters.
Because of the difficulties associated with interpreting logographic characters, languages that use logographic characters often include ruby characters that act as pronunciation guides for individual logographic characters. For instance, when a book written in Japanese includes a logographic character, a set of ruby characters may reside adjacent to the logographic character such that a person reading the text is able to read these phonetic characters if the user does not recognize the logographic character.
While the inclusion of ruby characters helps people read otherwise opaque portions of text, the inclusion of ruby characters does present several problems. First, these ruby characters may become somewhat distracting if a reader already knows the logographic character. In addition, given the permanent nature of physical books, when a publisher prints a book the publisher must decide on an amount of ruby characters to include. After the publisher releases the book, however, readers of a relatively low reading level may find that the publisher included too few ruby characters, while readers of a relatively high reading level may find the ruby characters unnecessary and potentially distracting.